I'm new to Ubuntu. After doing a full reinstall of 14.04 LTS on an Acer Inspire E5, the hard drive is not recognized as a bootable device, though it is recognized in general. Booting Ubuntu from a usb and running sudo fdisk -l yields the following:
WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x81d6cb14
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1953525167 976762583+ ee GPT
Partition 1 does not start on physical sector boundary.
Disk /dev/sdb: 4018 MB, 4018143232 bytes
255 heads, 63 sectors/track, 488 cylinders, total 7847936 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0021f04b
Device Boot Start End Blocks Id System
/dev/sdb1 * 2048 7847935 3922944 c W95 FAT32 (LBA)
This differs in a few ways from the output on a working ubuntu laptop I have access to, which has three partitions, and doesn't use GPT. However I don't know which difference is causing the problem, or why my laptop suddenly failed to boot from hard drive (I wasn't messing around with partitions before this occurred), nor how to fix it. I especially wonder that the laptop doesn't boot from /dev/sda1 despite fdisk showing it as bootable (I set this using cfdisk).
Are there any obvious flaws with my partition table that would prevent booting from the hard drive?
Edit: the output of sudo gdisk -l is as follows:
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 1953525168 sectors, 931.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): DAE150BD-1F2D-450E-BAA4-551D3ACA8047
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 3437 sectors (1.7 MiB)
Number Start (sector) End (sector) Size Code Name
1 2048 1050623 512.0 MiB EF00
2 1050624 1936922623 923.1 GiB 8300
3 1936922624 1953523711 7.9 GiB 8200
